:root{--bg:#f4f8f6;--card:#fff;--text:#19382e;--muted:#74877f;--line:#dfeae6;--g:#0b9b78;--g2:#19b78d;--red:#c95e56;--shadow:0 18px 55px rgba(25,74,57,.08)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--text);background:radial-gradient(circle at 8% 5%,rgba(66,172,127,.08),transparent 23%),radial-gradient(circle at 94% 13%,rgba(232,169,95,.06),transparent 22%),var(--bg);font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",Arial,sans-serif;line-height:1.65;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}svg{display:block}.page{width:min(1180px,calc(100% - 40px));margin:0 auto}
.site-header{position:sticky;top:0;z-index:1000;background:rgba(255,255,255,.94);backdrop-filter:blur(18px);border-bottom:1px solid rgba(214,229,223,.86)}.site-header .nav{height:82px;display:flex;align-items:center;gap:28px}.brand{display:flex;align-items:center;gap:12px;min-width:230px}.mark,.brand-mark{width:48px;height:48px;border-radius:15px;display:grid;place-items:center;flex:0 0 auto;color:#fff;background:linear-gradient(145deg,#17bd92,#078d6d);box-shadow:0 10px 24px rgba(11,155,120,.22)}.mark svg,.brand-mark svg{width:31px;height:31px}.brand strong{display:block;font-size:20px;line-height:1.18}.brand small{display:block;margin-top:5px;color:#7b8b85;font-size:12px;font-weight:650}.navlinks{display:flex;align-items:center;justify-content:center;gap:25px;flex:1}.navlinks a{padding:28px 0 26px;font-size:15px;font-weight:700;color:#49655b}.navlinks a span{position:relative}.navlinks a span:after{content:"";position:absolute;left:50%;right:50%;bottom:-11px;height:3px;border-radius:3px;background:linear-gradient(90deg,var(--g),var(--g2));transition:.2s}.navlinks a:hover,.navlinks a.active{color:#117b61}.navlinks a:hover span:after,.navlinks a.active span:after{left:0;right:0}.actions{display:flex;gap:10px}.btn{height:42px;padding:0 17px;border-radius:12px;border:1px solid #d6e6e0;background:#fff;display:inline-flex;align-items:center;justify-content:center;gap:8px;font-size:13px;font-weight:750;color:#315b4c}.btn svg{width:17px;height:17px}.btn.primary{background:linear-gradient(135deg,#159b78,#238864);border-color:#168b6d;color:#fff}.menu{display:none;border:0;background:transparent;font-size:25px;color:#315b4c}.mobile-share-link{display:none!important}
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.tool-shell{position:relative;background:#fff;border:1px solid #dfeae6;border-radius:28px;box-shadow:0 24px 72px rgba(27,82,61,.09);padding:28px;overflow:hidden}.tool-shell:before{content:"";position:absolute;left:0;right:0;top:0;height:4px;background:linear-gradient(90deg,#1ba77f,#58c29c,#efb469)}.tool-head{display:flex;align-items:flex-end;justify-content:space-between;gap:20px}.section-kicker{display:block;color:#2d9a77;font-size:10px;font-weight:850;letter-spacing:1.4px}.tool-head h2,.content-head h2{margin:4px 0 3px;font-size:23px}.tool-head p{margin:0;color:#81918b;font-size:11px}.mode-area{display:flex;align-items:center;gap:10px}.memory-status{display:flex;align-items:center;gap:7px;padding:8px 10px;border:1px solid #dce8e3;border-radius:10px;background:#fafcfb;color:#72867e;font-size:10px;font-weight:750}.memory-status i{width:7px;height:7px;border-radius:50%;background:#becbc6}.memory-status.active i{background:#2fa57e}.angle-switch{display:flex;padding:3px;border-radius:11px;background:#edf5f2}.angle-btn{height:31px;padding:0 11px;border:0;border-radius:8px;background:transparent;color:#758a82;font-size:10px;font-weight:850}.angle-btn.active{background:#fff;color:#1b795d;box-shadow:0 3px 10px rgba(27,80,61,.09)}
.calc-display{margin-top:20px;padding:18px 20px;border:1px solid #dce8e3;border-radius:18px;background:linear-gradient(145deg,#f8fbfa,#f1f7f4);min-height:136px}.display-top{display:flex;justify-content:space-between;gap:10px;color:#84958e;font-size:10px}.expression{margin-top:17px;min-height:39px;text-align:right;font-size:25px;font-weight:750;color:#294d40;word-break:break-all;overflow-wrap:anywhere}.preview{margin-top:7px;min-height:30px;text-align:right;color:#1c7c5f;font-size:18px;font-weight:800}.preview.error{color:#b35852;font-size:13px}.memory-row{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin-top:12px}.memory-row button{height:36px;border:1px solid #dce8e3;border-radius:10px;background:#fafcfb;color:#567067;font-size:10px;font-weight:800}.memory-row button:hover{background:#eef8f3;color:#22795e}
.pads{display:grid;grid-template-columns:1.08fr .92fr;gap:14px;margin-top:14px}.scientific-pad,.main-pad{display:grid;gap:8px}.scientific-pad{grid-template-columns:repeat(4,1fr)}.main-pad{grid-template-columns:repeat(4,1fr)}.key{min-height:52px;border:1px solid #dfe9e5;border-radius:13px;background:#fff;color:#34564a;font-size:13px;font-weight:800;transition:.14s}.key:hover{transform:translateY(-1px);border-color:#a9d0c1;box-shadow:0 6px 15px rgba(30,84,64,.06)}.key:active{transform:scale(.98)}.key.sci{background:#f6faf8;color:#34745d}.key.op{background:#edf7f3;color:#1f7c5f}.key.number{font-size:16px}.key.danger{background:#fff0ee;color:#b95a52;border-color:#efd8d4}.key.danger-soft{background:#fff7f2;color:#a97150}.key.equals{grid-column:span 2;background:linear-gradient(135deg,#159b78,#238864);color:#fff;border-color:#168b6d;font-size:18px}.calc-note{margin-top:13px;padding:10px 12px;border-radius:11px;background:#fff8ec;border:1px solid #f0dfbd;color:#7f6b4a;font-size:10px}.history-panel{margin-top:20px;padding-top:19px;border-top:1px solid #e7efec}.history-head{display:flex;align-items:center;justify-content:space-between}.history-head h3{margin:3px 0 0;font-size:15px}.history-head button{border:0;background:transparent;color:#6b8179;font-size:10px}.history-empty{margin-top:12px;padding:16px;border:1px dashed #dce7e3;border-radius:12px;background:#fafcfb;color:#899991;font-size:10px;text-align:center}.history-list{display:grid;gap:7px;margin-top:12px}.history-item{width:100%;display:flex;align-items:center;justify-content:space-between;gap:15px;padding:10px 12px;border:1px solid #e2ebe8;border-radius:11px;background:#fbfdfc;text-align:left}.history-item span{min-width:0;color:#73877f;font-size:10px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.history-item strong{flex:0 0 auto;color:#24785e;font-size:12px}
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.site-footer{margin-top:45px;background:linear-gradient(135deg,#063f41,#07574d);color:#d4ede8;padding:52px 0 24px}.footer-grid{display:grid;grid-template-columns:1.5fr repeat(3,1fr);gap:40px}.site-footer .brand{min-width:0;color:#fff}.site-footer .brand small{color:#afd3ca}.footer-brand p{max-width:300px;margin:14px 0;color:#bcd9d2;font-size:11px}.footer-pills{display:flex;gap:6px;flex-wrap:wrap}.footer-pills span{padding:5px 8px;border-radius:999px;border:1px solid rgba(255,255,255,.14);font-size:9px}.site-footer h3{margin:3px 0 12px;color:#fff;font-size:13px}.site-footer>div>div>a:not(.brand){display:block;margin:9px 0;color:#c4dfda;font-size:11px}.footer-bottom{margin-top:35px;padding-top:18px;border-top:1px solid rgba(255,255,255,.13);display:flex;justify-content:space-between;gap:20px;color:#b6d2cd;font-size:10px}.footer-bottom p{margin:0}
.share-modal{position:fixed;inset:0;z-index:2200;display:none;align-items:center;justify-content:center;padding:20px;background:rgba(5,35,33,.48);backdrop-filter:blur(6px)}.share-modal.show{display:flex}.share-dialog{width:min(520px,100%);border-radius:22px;background:#fff;overflow:hidden;box-shadow:0 26px 80px rgba(0,0,0,.2)}.share-head{display:flex;justify-content:space-between;align-items:center;padding:20px 22px;border-bottom:1px solid #e7efec}.share-head strong{display:block;font-size:16px}.share-head span{display:block;margin-top:3px;color:#81928b;font-size:10px}.share-head button{width:34px;height:34px;border:0;border-radius:10px;background:#eff5f2;font-size:22px}.share-body{padding:22px}.share-qr{display:flex;align-items:center;gap:16px}.share-qr>div{width:144px;height:144px;display:grid;place-items:center;border:1px solid #dfe9e5;border-radius:16px}.share-qr img{width:128px;height:128px}.share-qr h3{margin:0;font-size:14px}.share-qr p{margin:5px 0 0;color:#81938c;font-size:10px}.share-link{height:47px;margin-top:17px;display:flex;align-items:center;border:1px solid #dfe9e5;border-radius:11px;overflow:hidden}.share-link span{flex:1;padding:0 11px;color:#627970;font-size:10px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.share-link button{height:100%;border:0;border-left:1px solid #dfe9e5;background:#fff;color:#31765d;font-size:10px;font-weight:800;padding:0 15px}.copy-text{width:100%;height:42px;margin-top:10px;border:0;border-radius:10px;background:#218b69;color:#fff;font-size:11px;font-weight:800}.share-feedback{display:none;margin-top:9px;padding:9px;border-radius:9px;background:#eff9f4;color:#24795f;font-size:10px}.share-feedback.show{display:flex;gap:6px}.share-feedback.error{background:#fff1f0;color:#aa5b56}
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@media(max-width:1000px){.site-header .nav{height:74px}.actions{display:none}.menu{display:grid;place-items:center;margin-left:auto}.navlinks{position:fixed;top:74px;left:0;right:0;display:none;flex-direction:column;align-items:stretch;gap:0;padding:10px 20px 18px;background:#fff;border-bottom:1px solid #dfe9e5}.navlinks.open{display:flex}.navlinks a{padding:11px 4px}.mobile-share-link{display:block!important}.pads{grid-template-columns:1fr}.feature-strip,.examples-grid{grid-template-columns:repeat(2,1fr)}.footer-grid{grid-template-columns:1.2fr repeat(3,1fr);gap:22px}}
@media(max-width:680px){.page{width:min(100% - 24px,1180px)}.hero{padding:40px 0 28px}.hero h1{font-size:34px}.tool-shell{padding:16px;border-radius:22px}.tool-head{align-items:flex-start;flex-direction:column}.mode-area{width:100%;justify-content:space-between}.calc-display{padding:15px;min-height:126px}.expression{font-size:21px}.preview{font-size:17px}.memory-row{grid-template-columns:repeat(3,1fr)}.scientific-pad{grid-template-columns:repeat(4,1fr)}.key{min-height:47px;font-size:11px}.main-pad .key.number{font-size:15px}.feature-strip,.examples-grid{grid-template-columns:1fr}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.footer-bottom{flex-direction:column;gap:7px}.share-qr{align-items:flex-start}.share-qr>div{width:122px;height:122px}.share-qr img{width:108px;height:108px}}
@media(max-width:430px){.site-header .brand{min-width:0}.mark{width:42px;height:42px}.brand strong{font-size:16px}.brand small{font-size:9px}.scientific-pad{grid-template-columns:repeat(4,1fr);gap:6px}.main-pad{gap:6px}.key{min-height:44px;border-radius:11px}.footer-grid{grid-template-columns:1fr}.footer-brand{grid-column:auto}.share-qr{display:block}.share-qr>div{margin:auto}.share-qr>span{display:block;text-align:center;margin-top:11px}.topbtn{right:14px;bottom:14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition-duration:.01ms!important}}